Answer
(a) See the explanation below.
(b) See the explanation below.
Work Step by Step
a) The statement means that the line integral only depends on the two points -- that is, initial and final points -- which yield the same value.
b) If $F$ is a conservative field, it is known to be a vector field which does not depend upon the path taken. Mathematically, it can be defined as: $\nabla f=F$
