
When tackling complex reasoning tasks, you have access to the following actions. Use them as needed to progress through your thought process.

[ASSESS]

[ADVANCE]

[VERIFY]

[SIMPLIFY]

[SYNTHESIZE]

[PIVOT]

[OUTPUT]

You should strictly follow the format below:

[ACTION NAME]

# Your action step 1

# Your action step 2

# Your action step 3

...

Next action: [NEXT ACTION NAME]


system
An experimental airplane records its distance traveled in miles and changes in altitude in feet over a 5-hour test flight. The distance data points at the end of each hour from the start are as follows:
- Hour 0: 0 miles, 0 feet altitude
- Hour 1: 100 miles, 2000 feet altitude
- Hour 2: 250 miles, 1000 feet altitude
- Hour 3: 350 miles, 3000 feet altitude
- Hour 4: 420 miles, 2000 feet altitude
- Hour 5: 500 miles, 0 feet altitude

Determine during which hour the airplane exhibited the highest effective speed considering both horizontal distance and altitude change.
A) Hour 1
B) Hour 2
C) Hour 3
D) Hour 4
E) Hour 5

Present the answer in LaTex format: \boxed{Your answer}
user