What is the common name given to group $1$ elements?
(A) Alkali
(B) Alkaline
(C) Transition
(D) Noble gases

Hint: The elements present in the first group of the periodic table have only one unpaired electron with only one electron in their valence shell. This makes the atom donate electrons to achieve octet configuration and become stable. These are alkali in nature, so the elements in group $1$ are called alkali metals.

Complete answer: Group $1$ in the periodic table consists of the chemical elements: lithium, sodium, potassium, rubidium, cesium and francium. They are called alkali metals because these elements form alkalies in reaction with water. Alkalies are strong bases which are capable of neutralizing acids. The element francium of the first group is a natural radioactive isotope and is very rare in nature. As the alkali metals have only one valence electron, they actively participate in chemical reactions. They are usually found in nature combined with other elements. The alkali metals are highly ductile and are good conductors of heat and electricity. They have a silver like lustre. Among all the metallic elements, lithium is the lightest. The melting points of the alkali metals are low.
Thus, option (A) is the correct answer.

Note:
The alkali metals react readily with water vapor and the oxygen present in the atmosphere. They react vigorously with water and form strong caustic solutions releasing hydrogen gas. The alkali metals also react with various organic compounds, mainly those compounds which contain halogen or a hydrogen atom which is readily replaced.