Which three EL expressions, inserted at line 15, are valid and evaluate to "3"?

Given:

Which three EL expressions, inserted at line 15, are valid and evaluate to “3”? (Choose three.)

A.
${vals.2}

B.
${vals[“2”]}

C.
${vals.index}

D.
${vals[index]}

E.
${vals}[index]

F.
${vals.(vals.index)}

G.
${vals[vals[index-1]]}

Explanation: