You want to add the suffix 'ing' to the word 'trace'. Which of the following is the correct spelling of your new word?

The correct spelling of the new word formed by adding the suffix 'ing' to the word 'trace' is "tracing."

When adding 'ing' to a verb, the base form is typically used without any alterations, unless the base word ends with a silent 'e.' In the case of "trace," removing the silent 'e' gives you "trac," making it easier to directly add 'ing' to form "tracing." The ending 'ing' indicates an action in progress, aligning perfectly with the definition of the base verb "trace."

The other options would not adhere to standard English spelling rules. For instance, "traceing" incorrectly retains the 'e' instead of dropping it, while "traceling" introduces an unconventional form that does not exist as a recognized word. "Traced," on the other hand, is the past tense of the verb and does not fit the requirement of forming the present participle with 'ing.' Thus, "tracing" is the proper spelling you would want to use.