Miranda Did Not Realize She Could Be Pregnant Until She

Miranda did not realize she could be pregnant until she was already 14 weeks along; however,when she took a home pregnancy test it was negative.What is one explanation for this? 

A)  hCG levels peak in the second and third month of pregnancy and then drop off to levels that might not be detected by a home pregnancy test. 
B)  By the 12th week of pregnancy, estrogen and progesterone have levelled off so differences in them are no longer detected by a home pregnancy test. 
C)  Home pregnancy tests are only able to detect changes in a woman's body related to pregnancy for the first six weeks of pregnancy. 
D)  She was using her early morning urine for the test which tends to be lower in concentration of pregnancy hormones.