Whenever Dylan walks into his room, his roommate loudly blows an air horn, which startles Dylan. Dylan doesn't think this is funny, and after several such episodes, he tenses up and opens the door more slowly and carefully.
In this practical joke, the blast of the air horn that causes Dylan to jump out of his shoes is the .

Unconditioned stimulus

Explanation: Stimulus which triggers a natural or automatic response are Unconditioned stimulus. They differ from learnt response or condition stimulus. The apprehension or fear response developed or triggered in Dylan occurred naturally as soon as the the his roommate blew the horn. The horn blown to trigger such natural response is called Unconditioned stimulus while the startling response shown by Dylan is the Unconditioned or unlearnt response. Been fearful or apprehensive can occur naturally in an individual when one encounters a sudden or scary situation.

the correct answer is the following is a list of inventions made in the medieval islamic world, especially during the "islamic golden age" (8th to 13th centuries),[1][2] as well as the late medieval period, especially in the emirate of granada and the ottoman empire.

science and technology in the islamic world adopted and preserved knowledge and technologies from contemporary and earlier civilizations, including persia, india, china, and greece-roman antiquity, while making a number of improvements and innovations.