What is interesting about the pings that were sent to the european website?

option d is correct. corroborated sources of historical evidence   is necessary to validate a claim about an event in history.

historians tend to use written sources, but audio and visual materials as well as artifacts are important objects that supply information to modern historians.

historical sources are usually divided into two categories: primary and secondary sources. depending on the historian's intent, some sources shift their designation. determining what type of sources toimplement, and the level of credibility and reliability of those sources, is a significant step in critical thinking for the historian.

explanation:

the correct answer option is: weapons.

explanation:

tensions rose as the two opposing superpowers competed for 'weapons'.

referring to the cold war (1945-1991), the two superpowers, usa and ussr, experienced a phase of struggle and conflict with each other. these two superpowers considered each other as a threat to their survival and thus opted for policies to strengthen their positions.

the two superpowers never went to war with each other directly but competed for weapons to preserve their positions.