Hydrogen burns exothermically in oxygen What is the energy given out during the reaction: 2H2 + O2 -> 2H2O?

Given:
H-H bond: 436 kJ/mol
O=O double bond: 498 kJ/mol
O-H bond: 464 kJ/mol

A. -3226 kJ/mol
B. -884 kJ/mol
C. -486 kJ/mol
D. -442 kJ/mol​

Two metal blocks that have slightly different temperatures are placed next to one another. after five minutes, they both have lower but equal temperatures. according to the law of conservation of energy, what  most likelyhappened? energy was created inside the blocks.energy was destroyed inside the blocks.energy was absorbed into the blocks from outside the system.energy was transferred from the warmer block to the cooler block.