B) esta. esta typically refers to describing something like location whereas es describes the person's attributes. (ie, esta would be used with "she is in the store" and es would be used with "she is cute"
The next two terms are 216 and 648
answer : usted
explanation : usted means "you" to convey the formality of a relationship
Farm work is very difficult, for the endless hours spent making sure the crops are completely waters plowed and shipping them it can be a very difficult process.