I included in my solution that the reduction in expected business volumes is likely to be higher because the annuity sold by the company does not offer a guaranteed period. I saw in the solutions that this was not included is it a valid point to include? In my marked solution, I had written it vaguely and the marker failed to understand what I was trying to say.
The section of the marking schedule headed 'How to maintain profitability' does include [2] marks for the idea of offering annuities with a guarantee period. The marks for content are only awarded in full if the points covered are expressed very clearly at a level appropriate for the audience. As you've noted you felt you weren't as clear as you wanted in expressing the idea so this is likely why marks were not awarded. I hope this helps.