$2$

In Java, which of the following are not valid $($i$.$e$.,$ illegal $)$ variable names$/$identifiers:

I. $\_$yourName

II$.$ $workout$

III. $49$ years

Select one:

I only.

II only.

III only.

I and III.

I and II$.$

II and III.

I, II and III.

none of the above