You're going to have to provide more detail and explain exactly what went on here.
The very words "capital gains distribution" certainly imply that a mutual fund MADE that distribution to you and, as already explained, if you had that distribution automatically reinvested that doesn't change the fact that it's income to you. But now you've introduced the notion of "a sale of mutual funds" and suggesting that it "just happened", (which certainly can happen if you're not keeping current with what's going on), but if that "sale" was reported to you on a 1099-B then it's certainly "your" sale to report.
I previously asked you to name names and I'm adding to that "tell us exactly what went on here." You're just being too vague and to coy.
