The Kuiper belt and Oort cloud were first proposed by...? Mcqs

The Kuiper belt and Oort cloud were first proposed by...?

(A) Dutch astronomer Kuiper in 1950

(B) Dutch astronomer Jan Oort in 1950

(C) Dutch astronomer Kuiper Oort in 1950

(D) French astronomer Jan Oort and Kuiper in 1950