An article in the Economist magazine observes: One big reason to tie money to a commodity standard

Question:

An article in the Economist magazine observes: "One big reason to tie money to a commodity standard would be to limit its growth in order to protect against runaway inflation." Source: "on Gold and Golden Ages". Economist, September 11, 2012 (2 points)
a. Why would tying money to a commodity limit the growth of the money supply?
b. Would doing so limit inflation? Explain