A(n) state is comprised of a single, solitary state without consenting member governments.
a. devolved
b. unitary
c. executive
d. federal

The best answer to this question is: a unitary state (the correct answer is b).

A unitary state is a state with a central power, one where the government has the power and administration of the whole country and where there are no autonomous regions, such as states. The "opposite" of a unitary state is a federation.

River arrow on this map is pointing

productive most commonly means: achieving or producing a significant amount or result.

explanation:

productive can also mean:

producing or giving rise torelating to or engaged in the production of goods, crops, or other commodities.

these depend on how the word productive is used. most likely productive will mean   achieving or producing a significant amount or result.