Answer:
Option 4
Option 2
Explanation:
Given: The line segment AB and CD, P is the midpoint of AB which implies AP=PB and Q is the midpoint of CD which implies CQ=QD.
Also, It is given that P is point on AB, therefore there is no relation of point P with line segment CQ.
Hence, the invalid statement is
Segment AP is congruent to segment PQ.
Therefore, option (D) is correct.
Now, it is given that R is the midpoint of AP which implies AR=RP and S is the midpoint of QD which implies QS=SD
Now, AB≅CD (Given)
≅

PB≅CQ (Mid points are given)
Therefore, PA=QD
⇒PR=QS
Also, because PB≅CQ⇒PB+PR≅CQ+QS
⇒RB≅CS
⇒Segment RB is congruent to segment CS
Hence, option 2 is correct.