For this you can calculate the Fragement length from Host A to Router R1.
The data at TCP is 900B and 20 B header = 920 , abd it is now sent to IP Layer with 20 B Header so Ttal is 920+920= 940 , Now there is no beed of Fragement of Data as Maximum receiving MTU size for R! is 1024B so Host A to R1 is 940 B only.
You can stop here and se option 4 only satisfy this.