When is a series of terms said to be in the order of increasing extension?

(A) When each term in the series (except the first) denotes a class having more members than a class denoted by the term preceding it.

(B) When the class size gets larger with each successive term.

(C) When each term in the series (except the first) denotes a class having fewer members than the class denoted by the term preceding it.

(D) When the class size gets smaller with each successive term

Choose the most appropriate answer from the options given below :