Help me, please, with this extract
Two elderly couples were enjoying a friendly conversation in the garden when one of the men asked the other, "Fred, how was the memory clinic you went to a month ago?"
"Outstanding," Fred replied. "We (teach) visualization, association."
I suppose there we need Passive Voice, but will it be Present Perfect or Past Simple?
We were taught or We have been taught.
I understand the difference in meaning. I just want to know whether both of the answers work good in that context.