To answer this question, the user needs to be familiar with the concept of dialog controls and their naming conventions.
Now, let's go through each option and explain why it is right or wrong:
A. dal.: This option is incorrect because "dal" is not a standard prefix for dialog controls. The standard prefix typically used is "dlg" or "dia."
B. dia.: This option is incorrect because "dia" is not a standard prefix for dialog controls. The standard prefix typically used is "dlg" or "dia."
C. dil.: This option is incorrect because "dil" is not a standard prefix for dialog controls. The standard prefix typically used is "dlg" or "dia."
D. dlc.: This option is incorrect because "dlc" is not a standard prefix for dialog controls. The standard prefix typically used is "dlg" or "dia."
E. dlg.: This option is correct. "dlg" is the standard prefix for dialog controls. It is short for "dialog" and is commonly used in programming languages and frameworks.