The horizontal thrust on the ends of a two-hinged semicircular arch of radius R
carrying

A

a uniformly distributed load w per unit run over its right half span is
$$(\frac{2}{3})*(\frac{wR}{\pi})$$

B

a uniformly distributed load w per unit run over its entire span is
$$(\frac{4}{3})*(\frac{wR}{\pi})$$

C

a distributed load varying from zero at the left end to w per unit horizontal run at the right end,
is $$(\frac{2}{3})*(\frac{wR}{\pi})$$

D

All option are correct