What is the definition for “cadence”?

Which revision fixes the dangling modifier in this sentence? while reading a new mystery book, my dog curled up in my lap and slept. a.) curled up in my lap, my dog slept while reading a new mystery book. b.) while i was reading a new mystery book, my dog curled up in my lap and slept. c.) my dog, while reading a new mystery book, curled up in my lap and slept. d.) curling up in my lap while reading a new mystery book, my dog slept.