Firstly, it is important that you realise that radius of cylinder = radius of hemisphere.
Volume of solid = Volume of cylinder + volume of hemisphere
Volume of cylinder = π r² l
Volume of hemisphere = ⅔ π r³
π r² l + ⅔ π r³ = π r² (l + ⅔ r)
If you multiply the whole thing by 3, you will get
π r² / 3 (3l + 2 r)
Hence, A is the answer.