The correct option is A True
A compound adjective is formed when two or more words are joined together to form an adjective to modify the same noun. They are joined with a hyphen (-). It can be formed by joining an adjective and a noun with a hyphen. E.g. This rock-hard cake is impossible to eat. Here, rock is a noun and hard is an adjective and they are joined with a hyphen. Thus, option A is the correct answer.