Solution:
we have been asked to verify that -5, 1/2, and 3/4 are the zeroes of the cubic polynomial 
To verify that whether the given values are zeros or not we will substitute the values in the given Polynomial, if it will returns zero, it mean that value is Zero of the polynomial. But if it return any thing other than zeros it mean that value is not the zero of the polynomial.
Let 



Hence -5, 1/2, and 3/4 are not the zeroes of the given Polynomial.
Since sum of roots
But 
Hence we do not find any relation between the coefficients and zeros.
Anyway if the given values doesn't represents the zeros then those given values will not have any relation with the coefficients of the p[polynomial.
If the number k is greater than 3, we have the following inequality:

In order to evaluate k/3, let's divide the inequality by 3:

So the expression k/3 is greater than 1, therefore the correct option is D.
Answer:
3
Step-by-step explanation:
Using listing:


No other factors are possible.
Hence, 1, 3, 7 and 21 are factors of 21.
9 times 2.75 equals 24.75