7. If the physical size of the fluctuations is l, then the equation derived in the previous question shows that the angular size of these features will be smaller when q₀ is smaller. Hence it will be smaller in an open than in a closed universe.

Of course the low z approximation is not valid for the CMB fluctuations (originating from z~1000!), but the formula shows the sense of the deviations. A helpful sketch of the way in which space curvature affects the angular size is given on the MAP page referred to in the question.