
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
What is the units digit of the number

$$
1 \times 3 \times 5 \times \cdots \times 97 \times 99 ?
$$

(a) 1
(b) 3
(c) 5
(d) 7
(e) 9

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