What are some of the things that confuse children when learning to recognize letters? some letters look alike
some letters sound alike
an extra sound onto the end of a letter sound (e. g., saying, "bah" to label the "b" sound)
all of these can confuse children

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).

the answer is "a" although apex might say best book of the year.