The degree of the polynomial is

We have got polynomial, √3.

We can re-write it as, √3 x⁰ [∵ x⁰ = 1; any variable or number with exponent 0 gives 1 every time]

So, notice the exponent of x. Here, it is 0.

Since, degree of a term is sum of exponents of the variables that appears in it, and thus is a non-negative integer.

⇒ Degree of the polynomial = 0

Thus, option (d) is correct.