<span>B. Heat will flow from the iron to the lead to the copper until the temperatures are equal. because i don't really speak Italian </span><span> </span>
According to zeroth law of thermodynamics, when two systems are in thermal equilibrium with the third system then all of them are in thermal equilibrium with each other.
Hence, when copper block is placed adjacent to lead block and lead block is placed adjacent to iron block then heat will flow from hotter block to the colder block.
Thus, we can conclude that heat will flow from the copper to the lead and from the iron to the lead until the temperatures are equal.
It takes exactly 500 seconds for the sun's radiation to reach the earth or about 8 minutes (8.333333333333... to be exact). Just divide 150 million km by 300,000 km/s. Hope this helps