Answer:
Source A is not really supported by source B
Step-by-step explanation:
Source A depicts how a british tank was used to 'break through german trenches and take german prisoners', it shows that tanks were really useful in taking back territory. In source B, it is revealed by an ex commander that tanks only really boosted British soldiers, and that they were useless on uneven ground.
The truth is that tanks could be useful for taking over land and territory, but they only came into play towards the end of the war. By then, heavy artillery and attacks on no man's land made it really difficult for tanks to move swiftly across the 'huge craters and damaged trenches'. This contradicts source A's quote of 'the advance had been rapid'.
Tanks did boost ally morale and it is said that the germans ran away from the sight of it!, which is said in Source B. It should be said that Source A has been written by a tank commander, which would be biased as their only professional and job would be about tanks.
Hope this helps
(I got grade 8 in my gcses so you can trust me on this!)