Which best explains how a historian synthesizes evidence to reach a conclusion? o a. the historian makes comparisons among multiple primary and secondary sources. o b. the historian researches only one primary source and one secondary source. o c. the historian uses only secondary sources to support a claim. o d. the historian draws conclusions from a single primary source.

Sheila conducts an investigation to see how the amount of salt dissolved in water affects the density of the water whichstatement best describes the correct plan for her procedure? the density and the amount of water are controls, and the amount of salt and the type of salt are variablesthe amount of water and the amount of salt are controls, and the type of salt and the density are variablesthe type of salt and the amount of water are controls, and the amount of salt and the density are variablesthe type of salt and the density of water are controls, and the amount of salt and the amount of water are variableso