What does the superscript 2 plus mean in Upper C a Superscript 2 plus?

Question

Answer options with 5 options
A.
Ca lost 2 electrons

B.
Ca lost 2 protons

C.
Ca lost 2 neutrons

D.
Ca gained 2 protons

E.
Ca gained 2 electrons

Answer 1

A. Ca lost 2 electrons