Final answer:
In mathematics, like terms have the same variables to the same powers; thus, 12c, c, and -2c are like terms, and d and 4d are like terms as well. Option 1 is correct.
Step-by-step explanation:
Identifying Like Terms
In mathematics, like terms are terms that have the same variables raised to the same powers, though they may have different coefficients. In the case of 12c,d,c,−2c, and 4d, the goal is to pair terms with the same variable parts.
The like terms with the variable 'c' are 12c, c, and −2c. These terms can be combined because they all represent some multiple of the variable 'c'. On the other hand, the terms with the variable 'd' are d and 4d. Again, both of these terms can be grouped together because they represent multiples of the variable 'd'.
Therefore, Option 1 is the correct answer: 12c, c, −2c are like terms, and d, 4d are also like terms.