Maxwell's Reciprocal Theorem $1$

Consider a linear elastic body. When a concentrated gravity load $P=100kN$ is applied downwards to point A of the body, it causes point $B$ of the body to deflect upwards by $5mm.$ Based on this fact, a concentrated gravity load $Q=50kN$ applied downwards at point $B$ will cause point $A$ to deflect:

Select one:

a$.10mm$ downwards

b$.2\mathrm{.}5mm$ downwards

c$.2\mathrm{.}5mm$ upwards

d$.$ undetermined

e$.10$ mm upwards