Question

for which of the following would a prototype be hard to define? greatest sports teams of all time birds of north america fuel efficient cars feelings of parents when seeing child for the first time

Explanation:

A prototype is a typical example of a category. For "Greatest Sports Teams of All Time", what makes a team "greatest" is highly subjective (e.g., different sports, eras, criteria like wins, championships, fan base). In contrast, "Birds of North America" has biological classifications, "Fuel Efficient Cars" has measurable fuel - efficiency metrics, and "Feelings of Parents When Seeing Child for the First Time" is a more universal (though complex) emotional experience with common themes like love, awe, etc. The subjectivity and multiple conflicting criteria for "greatest sports teams" make its prototype hard to define.

Answer:

A. Greatest Sports Teams of All Time