1. The problem asks for the decimal equivalent of the binary number $1101_2$. 2. To convert a binary number to decimal, use the formula: $$\text{Decimal} = \sum_{i=0}^{n-1} b_i \times 2^i$$ where $b_i$ is the binary digit at position $i$ from right to left, starting at 0. 3. For $1101_2$, the digits from right to left are 1, 0, 1, 1. 4. Calculate each term: $$1 \times 2^0 = 1$$ $$0 \times 2^1 = 0$$ $$1 \times 2^2 = 4$$ $$1 \times 2^3 = 8$$ 5. Sum these values: $$1 + 0 + 4 + 8 = 13$$ 6. Therefore, the decimal equivalent of $1101_2$ is $13$. Final answer: C) 13