the set S of even integers.

Multiple Choice

BASIS STEP: $0$ in S

RECURSIVE STEP: If x in S$,$ then x $+2$ in S$.$

BASIS STEP: $0$ in S

RECURSIVE STEP: If x in S$,$ then x $2$ in S$.$

BASIS STEP: $0$ in S

RECURSIVE STEP: If x in S$,$ then x $+2$ in S or x $2$ in S$.$

BASIS STEP: $0$ in S

RECURSIVE STEP: If x in S$,$ then x $+2$ in S and x $2$ in S$.$