Which of the Following Situations Would Most Likely Require Observation

Which of the following situations would most likely require observation or scientific experimentation?

A) You want to find out what tools are available to protect your computer network from hackers.
B) You need to determine the average time it takes your line employees to produce a single piece of furniture.
C) You must find out which ten companies ranked highest for customer service in 2017.
D) You want to verify your supervisor's opinion on upgrading your department's accounting software.