(a) Binomial distribution: All integers from 0 to n.
(b) Exponential distribution: All real numbers from 0 to infinity.
(c) Negative Binomial distribution: All integers from r to infinity (note that you must wait at least r trials before observing the rth positive outcome).
(d) Normal distribution: All real numbers from negative to positive infinity.
(e) Geometric distribution: All integers from 1 to infinity (note that you must wait at least one trial before observing the first positive outcome).
(f) Gamma distribution: All real numbers from 0 to infinity (note that all r positive outcomes could, at least in theory, occur very near the beginning of the observation period).