Revolving doors commonly used in modern buildings were invented by which person?

Introduction / Context:
Revolving doors are a familiar feature at the entrances of hotels, office towers and shopping centres. They help control air flow, reduce energy loss and manage the flow of people. This question tests whether you know the inventor associated with this everyday architectural feature. Such questions link general awareness of inventions with names of individual inventors in engineering history.

Given Data / Assumptions:

• The question asks who invented the revolving door.
• Revolving doors are circular door systems that rotate around a central axis.
• We assume basic awareness of nineteenth and early twentieth century inventors related to building technology.

Concept / Approach:
To answer correctly, recall that an American inventor patented the revolving door in the late nineteenth century. His design aimed to solve problems such as strong drafts entering buildings through conventional doors. By remembering this historical detail, you can associate the revolving door with the correct inventor. The other names listed are real scientists and inventors but connected to different inventions in barometry, logic, batteries and lifts.

Step-by-Step Solution:
Step 1: Think of the name most commonly associated with the revolving door patent. Step 2: Recall that Theophilus Van Kannel is credited with inventing and patenting the revolving door. Step 3: Search the options for Theophilus Van Kannel and identify option C. Step 4: Confirm that the remaining options correspond to other well known inventions. Step 5: Choose Theophilus Van Kannel as the correct answer.

Verification / Alternative check:
Lucien Vidi is associated with the barograph, which records atmospheric pressure. John Venn is known for Venn diagrams in logic and set theory. Lewis Urry developed long lasting alkaline batteries and lithium batteries. Elisha Graves Otis is famous for elevator safety brakes and passenger lifts, not revolving doors. Only Theophilus Van Kannel is linked with the design and patent of the revolving door system, so cross checking the options confirms this choice.

Why Other Options Are Wrong:
Lucien Vidi worked in meteorological instruments, particularly the barograph, not in entrance systems.
John Venn contributed to mathematics and logic, and his name is remembered through Venn diagrams.
Lewis Urry improved battery technology rather than architectural door mechanisms.
Elisha Graves Otis introduced safety devices for lifts and is associated with elevators, not revolving doors.

Common Pitfalls:
Students sometimes confuse Otis, the elevator pioneer, with any building entrance mechanism, which can lead to the wrong answer. Another pitfall is to pick John Venn simply because his name is more familiar from mathematics, even though he did not work on engineering of doors. Associating Theophilus Van Kannel specifically with revolving doors is a good way to lock the correct answer into memory for exams and quizzes.

Final Answer:
Revolving doors were invented by Theophilus Van Kannel.