Three friends Sumesh, Vikas, and Rishi started a business with their monthly investment in the ratio of 2 : 3 : 4. After 4 months, Sumesh invested the same amount as before, and Vikas and Rishi, did only half of their investment. Find the ratio of their profit at the end of year?

a) 5 : 3 : 4
b) 3 : 3 : 4
c) 5 : 2 : 6
d) 6 : 4 : 3
e) None of these