Decide Which of the 5 Properties of a Commutative Group

Multiple Choice

Decide which of the 5 properties of a commutative group (closure, identity, inverse, associative, commutative) hold for
the given system.
- $$\begin{array} { c | c c c c } \| & 4 & 7 & 12 & 19 \\\hline 4 & 4 & 7 & 12 & 19 \\7 & 7 & 12 & 19 & 4 \\12 & 12 & 19 & 4 & 7 \\19 & 19 & 4 & 7 & 12\end{array}$$

A) All of them
B) None of them
C) Closure, identity, inverse, and commutative only
D) Closure, identity, inverse, and associative only