# A section of the periodic table is given below elements A , B and X, Y in two groups. Which of the bonds given below is the least polar.

$(A)\;AX \\ (B)\;AY \\(C)\;BX \\(D)\;BY$

Elecronegativity decreases down a group increases across a period but remains almost same along a diagonal therefore atoms A and Y have little difference in their electronegativities and hence AY bond is least polar.
Hence B is the correct answer.