what’s the answer to this math problem?plz answer

Answer:
B
Step-by-step explanation:
Graph B represents a linear function.
Notice that graph D also shows a line, but it is not the graph of a function, since it doesn't pass the vertical line test for functions.
Graph A shows a quadratic function, and graph C shows likely an exponential function. It is graph B the one that is linear, and a function as well.
Answer: It is B.
Step-by-step explanation:
A is a quadratic function
B is a linear function because it is a straight line and every input has exactly one output.
C is a is not straight
D failed the vertical line test.