• AEvery NFA can be converted to an equivalent DFA
• BEvery non-deterministic Turing machine can be converted to an equivalent deterministic Turing machine
• CEvery regular language is also a context-free language
• Every subset of a recursively enumerable set is recursive

(A) subset construction, (B) the standard NTM-to-DTM simulation result, and (C) regular⊂CFL are all true. (D) is FALSE: recursively enumerable sets are a broad class, and a subset of an RE set need not even BE recursively enumerable, let alone recursive.