Question

has the highest electronegativity
a cs
b pb
c br
d se

Explanation:

Electronegativity increases across a period from left to right and decreases down a group. Cs (Cesium) is an alkali metal with very low electronegativity. Pb (Lead) is a metal with relatively low electronegativity. Se (Selenium) and Br (Bromine) are non - metals. Br is to the right of Se in the periodic table. According to the periodic trend of electronegativity (increases across a period), Br has a higher electronegativity than Se.

Answer:

C. Br