Explanation
Choice A is the best answer. The word "investigate" means examine. According to the text, muons possess properties that defy the conventional understanding of particles, which has led to numerous studies and experiments among scientists. The fact that their properties are the subject of much academic inquiry shows how fascinating they are to examine.
Choice B: "increase" means multiply. However, it would not make any sense, since multiplying muons would not lead to many studies and experiments on them.
Choice C: "sketch" means outline. Sketching muons does not necessarily lead to studies and experiments about them.
Choice D: "invent" means devise. However, it does not make sense to invent a particle that is found in nature and is not artificially created.
✨ Expert's Tip ✨
Identify the properties that make them fascinating and consider what they led scientists to do (“... numerous studies and experiments ...”).