How 2 is the correct answer? i need to know the explanation

i have to report this, it doesn't relate to biology

the oldest known insects are believed to live around 400 millions ago as suggested by the fossil records.   some plants having woody stems also evolved during this time.

after the evolution of insects the first four legged species or the tetrapods evolved in shallow freshwater habitats from the intermediate species approximately 397 million years ago. the tetrapods went on conquering the land giving rise to amphibians, reptiles, mammals and birds.

the major split in tetrapods first occurred 340 million years ago branching off from amphibians.

363 million years ago when the carboniferous period began the insects started roaming on land and taking flights, following which the four limbed tetrapods adapted in the terrestrial habitat.

the ems is the abbreviation for the emergency medical services. it is a service provided by a group of medical professionals specialised doctors and other healthcare staff.

any one can call 911 in case of any medical emergency and a group of health care professional will come and give the treatment required. every day the ems staff receive many phone call, which are related to different types of medical emergencies, out of which 25-28% are exclusively related to the respiratory issues.

so, the correct answer is 25-28%.