Simplify 24m^8n^7+20m^3n^4-4mn/12m^2n^5

[] 2m^6n^2+5mn-3mn^4
[] 2m^6n62+5mn/3-mn^4/3
[] 2m^6n^2+5m/3n-1/3mn^4
[] 2m^6n^2+20m^3n^4-4mn