A Martian Farmer Looks Out into the Barnyard and Sees

Multiple Choice

A Martian farmer looks out into the barnyard and sees tribbles (which have one head and four legs) and chalkas (which have one head and seven legs) . She says to her son, "I count 135 heads and 738 feet. How many tribbles and how many chalkas are out there?" ​

A) 138 tribbles and 46 chalkas
B) 79 tribbles and 56 chalkas
C) 69 tribbles and 66 chalkas
D) 99 tribbles and 36 chalkas
E) 66 tribbles and 138 chalkas