Correct option is A
Effect of type and size of aggregate in strength of concrete:
Aggregate shape affects their packing and hence void content also. The crushed stone and gravels give higher strength.
Angular aggregate provide very good bond than the earlier two, is most suitable for high strength concrete and pavements however requirement of cement paste is relatively more.
In case of rounded aggregates, development of bond is poor as interlocking between particles is less, thus unsuitable for high strength concrete.
Larger size aggregates give lower surface area for development of gel bonds which leads to low strength.
