Decimal-to-BCD Encoder
A decimal-to-BCD (Binary-Coded Decimal) encoder is a combinational circuit that converts a decimal number into its equivalent BCD representation. BCD is a binary representation of decimal numbers where each decimal digit is represented by a 4-bit binary code.

Explanation:
To understand the number of outputs that a decimal-to-BCD encoder will have, we need to analyze the BCD representation for decimal numbers.

BCD Representation:
In BCD representation, each decimal digit (0-9) is represented by a 4-bit binary code. Since we have 10 decimal digits, the BCD representation will require 4 bits for each digit.

Number of Decimal Digits:
The number of decimal digits can vary depending on the decimal number we are encoding. For example, the decimal number 5 only has one digit, while the decimal number 567 has three digits. To determine the maximum number of digits that a decimal number can have, we need to consider the maximum value that can be represented in the given system.

Maximum Decimal Value:
In decimal system, the maximum value that can be represented with 'n' digits is (10^n) - 1. For example, with one digit, the maximum decimal value is 9 (10^1 - 1), and with three digits, the maximum decimal value is 999 (10^3 - 1).

Number of Outputs:
Since each decimal digit requires 4 bits in BCD representation, the number of outputs will be equal to the number of decimal digits multiplied by 4.

Example:
Let's consider a decimal number with 6 digits. In BCD representation, it will require 6 * 4 = 24 outputs. Similarly, a decimal number with 3 digits will require 3 * 4 = 12 outputs.

Conclusion:
Therefore, the correct answer is option 'A' - 4 outputs. It is important to note that the number of outputs may vary depending on the number of decimal digits in the input number, but the options provided do not account for this variation.