Maximum downdrafts in a microburst encounter may include horizontal winds near the surface as strong as:

The correct answer highlights that in a microburst encounter, maximum downdrafts may produce horizontal winds near the surface that can reach up to 45 knots. This is significant because microbursts, which are a type of intense localized downdraft, are characterized by their rapid changes in wind speed and direction.

The presence of winds of this magnitude represents a critical hazard for aircraft, particularly during takeoff and landing phases when operations are closest to the ground. Understanding that these powerful winds can occur helps pilots and dispatchers take necessary precautions to ensure safety during adverse weather conditions.

The other options represent wind speeds that, while strong, fall short of the dangerous threshold defined for microbursts. An awareness of the potential for 45 knots allows flight crews to factor in this risk and make informed decisions regarding flight operations in affected areas, emphasizing the need for precise weather data when planning flights in potentially severe weather regions.