Hydrogen chloride molecule contains a
A. Covalent bond
B. Double bond
C. Coordinate bond
D. Electrovalent bond

Hint: A molecule in which the involved atoms have similar electronegativity shares their electrons and forms covalent bonds.
A molecule in which the involved atoms don't have similar electronegativity gain and lose electrons and form an ionic bond.

Complete step by step solution:Here in this question, we are given a hydrogen chloride molecule and we have to find out its bond type.
Atoms are small-sized particles of a chemical element.
These combine to form molecules.
They combine by forming chemical bonds.
Chemical bonds are formed when electrons are near two or more nuclei.
A. Covalent bond
A covalent bond is a more familiar kind of bonding.
In a covalent bond, the electrons are placed in an area between the two nuclei and are shared by them.
Electronegativity means the ability of a chemical species to draw an electron toward them.
In these, the atoms involved have similar electronegativity or have little difference in their electronegativities.
It means that one atom does not draw the electron towards itself completely.
The electronegativity of H and Cl is 2.2 and 3.16 respectively.
The electronegativity difference is 0.96 which is small.
So, the bond present in HCl is covalent.

B. Double bond
H has only one electron that it can share to form a bond. For a double bond, two involved atoms share two pairs of electrons.
So, B is incorrect.

C. Coordinate bond
This is a kind of covalent bond in which the bond is made by sharing an electron pair from one of the involved atoms.
It means that both the shared electrons are contributed by this atom.
It is also named a dative bond.
HCl doesn't involve this type of bonding.
So, C is incorrect.

D. Electrovalent bond
This is ionic bonding in which the atoms involved gain and lose electrons to form this.
It needs in the case of a diatomic molecule like HCl, one electron contributor, and one electron acceptor.
This involves the transfer of valence electrons between atoms.
HCl doesn't involve this type of bonding.
So, D is incorrect.
So, the HCl molecule contains a covalent bond.

So, option A is correct.

Note: There are two types of covalent bonds i.e., polar and nonpolar.
The HCl is a polar covalent bond because chlorine has a higher electronegativity than hydrogen. So, it drags the shared pair of electrons towards itself.
It obtains a partial negative charge and hydrogen obtains a partial positive charge. So, the bond is polar. The charge is partial as the electron pair has been drawn partially by chlorine not completely.