True$/$False$.$ Briefly justify your answer for each statement: $($You don't need a formal proof here.$)$

a$)1.$ Any subset of a decidable language is recognizable.

b$)2.$ Any superset of an undecidable language is uncountable.

c$)3.$ There exists a language that is both countable and undecidable.

d$)4.$ Let $L$ be a regular language, and $S_L$ be a subset of $L.$ Then $S_L$ is Turing$-$recognizable.

e$)5.$ If $A_{TM}$ reduces to a language $L,$ then $L$ contains infinitely many strings.