Al- Khwarizmi is the correct answer.
Al Khwarizmi was Persian mathematician and astronomer. He was born around 800 AD and died in 850 AD during the Abbasid Empire. His work such as Compendious Book on Calculation by Completion and Balancing and about Hindu numerals were famous throughout Europe. He created astronomical tables for calculating the position of eclipses and planets. His book was widely read by the European mathematicians. In his book AL-Jabr Wal' Muqibla, he introduced his own numeral system and Arabic numerals. His books were translated into latin and greek and most of these books were named "So said Algorizmi". The word algorithm is derived from Algorizmi and algebra is derived from Al-Jabr. He used to work at the House of Wisdom and was most famous mathematicians of medieval times.
s the president shall be commander in chief of the army and navy of the united states, and of the militia of the several states, when called into the actual service of the united states; he may require the opinion, in writing, of the principal officer in each of the executive departments. sooo yeahhh
the answer is a) to be able to obey them.