I need some help finding out what symbol I use for a high yield S&P 500 Index fund.

Im not sure which one I pick, Im using CIBC Investments and when I put in S&P500 all I get is 3 answers: SP500MUN: S&P-500 Momentum index (US Dollar) Net Total Return, SP500MUP: S&P-500 Momentum index (US Dollar) and SP500MUT: S&P-500 Momentum index (US Dollar) Gross total return.

Witch one do I pick? Because Im kind of new to this whole investing thing and I worry that being Canadian may hinder my chances.