A 2 m long beam BC carries a single concentrated load at its mid span and is simply supported at its end by two cantilevers AB = 1 m long and CD = 2 m long as shown in figure. The shear force at end A and bending moment at end D of the cantilever, respectively will be -

Correct option is D

The given beam is:
Consider FBD of beam BC:
Σfy = 0
RB + RC = 100
ΣMB = 0
RC × 2 = 100 × 1
⇒ RC = 50 kN and RB = 50 kN
Consider FBD of beam AB and CD:
ΣFy = 0 ⇒ RA = 50 kN
ΣMA = 0 ⇒ 50 × 1 = MA
= MA = 50 kN.m
shear force A is reaction at A i.e. VA - RA = 50 kN.
ΣFy = 0
⇒ RD = 50 kN
ΣMD = 0
⇒ 50 × 2 = MD
MD = 100 kN.m
BM at D is MD = 100 kN.m