Final answer:
The form 2y+1-n is an algebraic expression, which is a combination of variables, numbers, and operations without an equal sign.
Step-by-step explanation:
The mathematical form 2y+1-n is known as a algebraic expression. An algebraic expression is a combination of variables, numbers, and at least one arithmetic operation (like addition, subtraction, multiplication, division). In contrast, an algebraic equation equals an expression to a value or another expression, and often includes an equal sign.
A term is typically a single variable or number, or the product of a variable and a number, so 2y+1-n is more complex than a single term. Thus, the correct answer is B) Algebraic Expression.