Question is fine and the answer is C.
C's present routing table is like - (∞,6,0,3,5,∞) [Assuming its second iteration]
On receiving B as -(15,0,18,12,16) & D as- (16,12,6,0,9,10) & E as- (17,16,13,19,0,14)
C will attempt to minimize its delays to A-
Using B For A, delay of C-B=6 & B-A=15, total=6+15=21, Since ∞>21, Update C's table as (21,6,0,3,5,∞)
Using D For A, delay of C-D=3 & D-A=16, total=3+16=19, Since 21>19, Update C's table as (19,6,0,3,5,∞)
Using E For A, delay of C-E=5 & E-A=17, total=5+17=22, Since 19<22, No Update in C's table (19,6,0,3,5,∞)
Similarly minimize delays to F-
Using B For F, delay of C-B=6 & B-F=16, total=6+16=22, Since ∞>22, Update C's table as (19,6,0,3,5,22)
Using D For F, delay of C-D=3 & D-F=10, total=3+10=13, Since 22>13, Update C's table as (19,6,0,3,5,13)
Using E For F, delay of C-E=5 & E-F=14, total=5+14=19, Since 13<19, No Update in C's table (19,6,0,3,5,13)
Final table- (19,6,0,3,5,13)
P.S- I have skipped checking for B,D,E as they are already minimum, but they should be checked in each iteration.