Let us check each statement one by one
a) Sb has a lower ionization energy but a higher electronegativity than I. : As per values given : Definitely Sb has lower ionization energy however the electronegativity of Sb is lower than that of iodine
b) Sb has a higher ionization energy but a lower electronegativity than I. FAlse:
Sb has lower ionization energy than I
c) Sb has a lower ionization energy and a lower electronegativity than I. True
d) Sb has a higher ionization energy and a higher electronegativity than I. False
To determine how many protons are present, simply know or use the following equation
X = number of protons
Y = number of electrons
Z = formal charge of the element
X - Y = Z = 0 for a neutral atom
X - Y = 2
Then to solve for x
X = Y + 2.
This means that we would need an additional 2 more protons than electrons.