Use the scenario to answer the question.

thea is tracking the output and income of her farm. each of her cows produces 4 gallons of milk per day, and she receives $1 per gallon. she is given a government subsidy payment of $70 per day to with farm bills, but she needs more money to operate the farm.

thea wants to determine how many more cows she should buy in order meet her costs. she creates the expression $1cow⋅x cows+$70 to represent the amount of money her farm brings in each day.

is thea's expression correct?

no, her expression is incorrect. her rate of $1cow is incorrect. because each cow produces 4 gallons of milk per day, she makes $4 per cow each day. her expression should be $1gallon⋅4gallonscow⋅x cows+$70.
no, her expression is incorrect. the constant of $70 should not be included in the expression because it will incorrectly add $70 to every cow each day. her expression should be simply $1 per cow⋅x cows.
yes, her expression is correct. her rate of $1 per cow is correct, because it is possible to multiply this rate by the number of cows to find how much each cow makes in a day. the constant of $70 is needed because it is part of the farm's income each day.
no, her expression is incorrect. since each cow produces 4 gallons of milk a day, she needs to divide her rate of $ 1 per cow by 4 times the number of cows she has. her expression should be $1 per cow÷(4⋅x cows)+$70.