is that a start you can use or do you need more help?Code:#include <stdio.h> #include <stdlib.h> /*for exit funcion,& strtol*/ int main(void){ int distance_source, gas_amount_pkm, gms_amount_pkm_temp, pollutant_no,long_input; char *loc; /*for strtol*/ printf("%s\n","1. Carbon Monoxide\n 2. Hydrocarbons\n 3. Nitrogen oxides\n 4. Non methane hydrocarbons"); if((fgets(input,sizeof input,stdin))==NULL){ printf("error occured getting input\n"); exit(1); } long_input=strtol(input,&loc,0);