Which statement about silver ag metal is least reliable

The choices for this question can be found elsewhere and as follows:

Silver is a transition metal with electrons in the d shell.
Silver atoms have 47 protons in their nuclei.
Silver atoms commonly form ions with a +1 charge.

I think the correct answer is the last option. The least reliable information would be that silver atoms commonly form ions with a +1 charge.

The correct answer is "atomic weight".