The Surface Temperature of Venus Was First Measured By

Multiple Choice

The surface temperature of Venus was first measured by:

A) direct temperature measurement at the planet's surface by the Soviet lander Venera 7.
B) infrared emission from the lower atmosphere of Venus by astronomers at the Canada-France-Hawaii telescope on Mauna Kea.
C) radio emission from the planet's surface by the Arecibo radio telescope in Puerto Rico.
D) microwave emission from the planet's surface by the American spacecraft Mariner 2.