Hi,
Yes you can choose "Two or more Certificates" option. If both have been evaluated by WES. I have the same case.
I have a 3 years bachelors degree (evaluated by WES as equivalent to 4 years bachelor)
And a one year diploma full time which i studied in a different country ( evaluated by WES as 2 year diploma program).
Just make sure, that WES evaluates both and gives you Canadian Equivalency Qualification for both of them.
Hope this helps.