Explanation
To decipher the code, we need to observe the pattern between the code words and their corresponding actual words.
In the given code, each letter in the word "PROFESSOR" has been replaced by the letter that comes three places after it in the English alphabet. For example, the letter P has been replaced by the letter O which is three places after it in the alphabet.
Using the same pattern, we can decipher the code for "DMSDQDC". We need to find the letter that comes three places after each letter in the word "Entered".
For the first letter E, the letter that comes three places after it in the alphabet is H. Similarly, for the second letter N, the letter that comes three places after it in the alphabet is Q. By following this pattern, we get the code "DMSDQDC" for the word "Entered".
Hence, the correct answer is option A: Entered.