Answer:
Option (d) is correct.
Radius of given equation is 18 units.
Explanation:
Given : The equation of circle as

We have to find the radius of given circle.
Consider the given equation of circle

The standard equation of circle with center (h,k) and radius r is given as

Rewriting in standard form, we have,
Grouping x and y variables, we have,

Convert x terms to perfect square term by adding 49 both side, we have,

Simplify, we have,

Convert y terms to perfect square term by adding 25 both side, we have,

Simplify, we have,

Thus, standard form is

Thus, radius of given equation is 18 units.