Explanation:
domain : the interval or set of all valid x-values.
range : the interval or set of all valid y-values (function result values).
A is correct
theoretically all real numbers are valid as x. but for this application of the function only non-negative integer values make sense (e.g. half a cycle does not make any sense).
C is correct
via A we are allowing all real numbers to be valid input values, so, we have to allow also all real numbers to be valid output (function result) values.
D is correct
the y-intercept means the y-value, when the function curve intersects the y-axis.
this is only possible, when x = 0.
5⁰ = 1
as any x⁰ = 1
F is correct
the bigger x, the bigger 5^x.
and the smaller x, the closer y, the function result, gets to 0. particularly, when we allow negative input values (as we said in A).