When a leaf is composed of small leaf like structures like leaflets, it is called as
A) Simple leaf
B) Complex leaf
C) Compound leaf
D) Semi-compound leaf

Hint:A leaflet (or foliole) is a leaf-like structure of the plant which grows not on the main stem or branch of the plant but on the petiole (leaf branch).

Complete answer:
Let us look at each option one by one.
A leaf that is not divided into subunit leaflets is called a simple leaf. It is attached to the plant via the petiole. Therefore, this option is incorrect.
Palmately compound leaves are known as complex leaves. These leaves have leaflets attached to the petiole in the shape of the hand. Complex leaves are a type of compound leaves and are therefore an incorrect option.
A leaf that is divided into subunit leaflets is called a compound lead, While the leaf itself is attached to the plant via the petiole, leaflets are attached to the plant via branches on the petiole. Therefore, this is the correct option.
Semi-compound leaves are lobed leaves which contain distinct projections from the center of the midrib containing individual veins for each projection. These leaves do not contain leaflets. Therefore, this option is incorrect.

Thus, the correct answer is option (C) Compound leaf.

Note:Simple leaves can be distinguished from compound leaves by locating the lateral buds present at the base of the petioles. While simple leaves contain a distinct petiole at the base of the petiole, leaflets of the compound leaf do not contain buds at the base of the stalk connecting them to the petiole; but the base of the petiole of the compound leaf does contain a lateral bud.