In subsistence farming, people generally grow a]only enough to feed their families b]cash crops that command high prices c]crops that are shipped to other countries d] dairy products for city dwellers

In substinence farming, people generally grow A) only enough to feed their families. 

In subsistence farming , people generally grow : a. Only enough to feed their families

The output of subsistence farming is usually very low and leaving no residual stock that could be used for trading or selling

hope this helps

What exactly do you mean