Place Value Practice: Convert 1 Hundred, 3 Tens, and 9 Ones to a Number

To solve this problem, we'll follow these steps:

• Step 1: Assign each number to the correct place value.
• Step 2: Construct the number by adding each weighted position.

Now, let's work through each step:
Step 1: We have three digits to place:
- We assign **9** to the ones (units) position.
- We assign **3** to the tens position.
- We assign **1** to the hundreds position.

Step 2: Combine these placements:
- The number is constructed as follows: $100 \times 1 + 10 \times 3 + 1 \times 9$
- This simplifies to: $100 + 30 + 9 = 139$.

Upon comparing with the provided answer choices, the correct choice is clearly $\boxed{139}$.

Therefore, the solution to the problem is $139$.