how many drops per second?

An HP printhead can fire more than how many drops per second?

A.
30 trillion

B.
30 thousand

C.
300

D.
30 million

Explanation:
Reference:http://www.amazon.co.uk/HP-Photosmart-Printer-Wireless-Print/dp/B005IY1RDM(why
original HP inks, second para)