When you say "the statement is vague", it means the statement is lacking in detail. When you say "the statement is obscure", it means the statement is difficult to make out or define (i.e. vague), or not clearly expressed or easily understood, or not well-known. (obscure has a few meanings that could fit a description of a statement) When you say "the statement is muddled", it means the statement is not clear or coherent. When you say "the statement is ambiguous", it means the statement can have more than just one meaning. Since the first part of the sentence is "I can't decide on the meaning...", it suggests that the sentence probably has more than just one meaning and you are not able to choose which meaning the sentence is trying the convey. So the most appropriate answer would be "ambiguous".

favoritism, favouritism, secernment ,I just knew these ,wish it helps u