"I wasn't able to answer this q since I didn't know the value of '\u0042' "
A couple of things: first, although you didn't know the value of '\u0042', you should still be able to eliminate the choices that read "prints A", "prints A,B,C,Default", and "prints Default" because those choices do not rely on your knowing the value of '\u0042'; those choices rely on your knowledge of the switch statement. Once you eliminate those choices, you have a 50-50 chance between "Prints Default A,B,C" and "Prints B,C".
Second, in the years that I've been programming, I've memorized only a few values from the ASCII table (which maps into Unicode):
Briefly, I've memorized NUL because it is used so much by C/C++ programmers; LF and CR from parsing files, and although I know one is 10 and the other 13, I'm never really sure which is Rosencrantz and which is Guildenstern; (Space) because it is important and an island unto itself; '0' because I can figure out all the other base 10 digits by adding 48 to their offsets; and 'A' and 'a' because similar to numbers, I can figure out all upper and lower case letters by adding 'A' or 'a' to their offsets in the alphabet.
In effect, I can quickly figure out 66 ASCII values by knowing seven values in the ASCII table. These are perhaps also the 66 most commonly found and important to know.
Finally, all I really know from the table are the ASCII values (e.g., 'A') and their decimal equivalents (e.g., 65). I do a quick hex computation as needed.
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