For easiest cloning, one needs to get vector with
A. Single cloning site
B. Multiple cloning site
C. Few cloning site
D. No cloning site at all
The vector needs to have very few, preferably single, cloning site (short segment of DNA which contains restriction sites) for the commonly used restriction enzymes. Presence of more than one recognition sites within the vector will generate several fragments, which will complicate the gene cloning.
NCERT Biotechnology: Principles And Processes page number 199, point (iii)