When do HP Care Pack Services need to be registered?

When do HP Care Pack Services need to be registered?

A.
within 10 days after the purchase of the care pack

B.
within 10 days after the purchase of the hardware

C.
within 30 days after the expiration of the warranty

D.
within 90 days after the purchase of the hardware

Explanation:
Reference:http://www8.hp.com/h20195/v2/GetPDF.aspx%2F4AA5-1146ENW.pdf(See the Page
#03, Last Paragraph, 2ndLast line).