Answer :
Marcus was suspicious of and confused by his friend's frequent lies is incorrect sentence
What is a sentence?
A sentence consist of words that have subject and verb which convey information that have meaning.
For a sentence to be correct, the subject and verb must agree with one another in the statement and if If the subject is in plural form, the verb also should be in plural form.
Therefore, Marcus was suspicious of and confused by his friend's frequent lies is incorrect sentence because the right conjunction was not use.
For more details on sentence, check the link below.
https://brainly.in/question/2582195