1. The control character "\0" is known as the null character. 2. It is used primarily in programming languages like C and C++ as a string terminator. 3. This means "\0" marks the end of a string of characters in memory, signifying where the string finishes. 4. It is not used for character alignments, end of line symbols, line breaks, or position displays on screens. 5. Therefore, the correct answer is that "\0" is used as a string terminator, which corresponds most closely to: end of line symbols (but technically it marks the end of a string, which is why none of the given exact options are perfectly accurate). Final answer: None of the provided options precisely describe the control character "\0" usage; however, it is best identified as end of line symbols in the context given.