Which sentence includes faulty coordination?
a. my dad attended my high school many years ago, but he transferred out his junior year.
b. many parts of the school have been restored, and they look much as they did when the school opened.
c. my school is the oldest in our town, and it is three stories high.
d. the middle school in our neighborhood is old, but it is not nearly as old as my high school.

check this quizlet it might have the answer

the following key ideas correctly express the key sentence.

restate key idea: most people can learn to swim in ten short lessons.

restate key idea: the majority of water-accident victims require mouth-to-mouth breathing.

restate key idea: an empty, tightly closed gallon jug will support a tired swimmer.  

restate key idea: first aid is to prevent accidents as well as assist in rescue.

explanation: the key idea needs to have the same topic as the key sentence (drowning and safety).