Which statement best describes the limits of science? a. science cannot answer any abstract questions. b. usually science can answer only mathematical questions. c. science cannot answer religious questions. d. when used properly, science can answer any question.

The only correct statement which describes the limits of science is the first option from the scale represented above - a. science cannot answer any abstract questions as its aim is to bring direct or the closest explanation to the concrete object. For addition I would say that solving abstract questions is a deal for rhetoric.