Question $6$

Given the function $g(x1,$dots,$x4)={\displaystyle \underset{?}{\overset{?}{}}}m(0,2,4,5,10,11,13,15),$ answer the following questions:

a$)$ How many possible implicants for $g?$

b$)$ Find all prime implicants.

c$)$ Find all essential prime implicants.

d$)$ Derive the equivalent logical expression with the minimum number of Literals.