Given that $\displaystyle \lim_{x \to a} f(x)=0,\ \lim_{x \to a} g(x)=0,\ \lim_{x \to a} h(x)=1,\ \lim_{x \to a} p(x)=\infty,\ \lim_{x \to a} q(x)=\infty$.

Which of the following limits are indeterminate forms? For those that are not an indeterminate form, evaluate the limit where possible. Enter I to indicate an indeterminate form, INF for positive infinity, NINF for negative infinity, and D for the limit does not exist or we don't have enough information to determine the limit.

(a) $\displaystyle \lim_{x \to a} [f(x)-p(x)]=$

(b) $\displaystyle \lim_{x \to a} [p(x)-q(x)]=$

(c) $\displaystyle \lim_{x \to a} [p(x)+q(x)]=$