Pitch angle and Climb angle

[raul.jetpilot]

Another one confusing me:

Question ID 1452 Bristol Database
A jet aeroplane is climbing at a constant IAS and maximum climb thrust, how will the climb angle / the pitch angle change?

It seems very obviuos that climb angle will reduce mainly due to the loss of Thrust associated with altitude raise and the need to keep IAS constant...but I can't find a rationale for pich angle...because, it seems that I am not understanding very well the difference between climb angle and pitch angle...

Any help on this one??????

Kind Regards to all helpers

Thanks