How does it affect U.S. investors investing in European securities if the dollar is expected to depreciate against the euro?

It does not affect them.

It makes them worse off, since it decreases the dollar cash flow from their European investments.

It makes them better off, since it decreases the dollar cash flow from their European investments.

It makes them better off, since it increases the dollar cash flow from their European investments.

It makes them worse off, since it increases the dollar cash flow from their European investments.