The Tone of Phrasing Used in a Report's Introduction Section

The tone of phrasing used in a report's introduction section

A) is not really important: the real tone is set in the analysis sections.
B) is not really important because the chosen facts and arguments essentially set the tone.
C) is important because the introduction should set the tone for the entire report.
D) should be kept totally neutral so that the report's stance or conclusions are not inadvertently revealed.