Biology question (OCR A 5.1.2 excretion)

the question is:
the hormone hCG can be detected in during using pregnancy tests
which of the following properties of the hormone hCG allows it to be detected in urine?
A - hCG is a polar molecule
B - hCG has a molecular mass of less than 69,000
C - hCG is a polypeptide
D - hCG binds to cells using glycoproteins

Remember to break down the question, and link your knowledge. Question states ‘detected in urine’, so HCG must be transferred from blood to urine. There is only one process that does this - ultrafiltration. As large plasma proteins, albumin, are unable to pass through fenestrations of the capillary in the glomerulus, it is related to the size.
B