Question

one proposed boundary between earths atmosphere and outer space is the kármán line, 100 km above sea level. based on the work of physicist theodore von kármán, this line marks the theoretical height at which an aircraft no longer remains aloft using the force of lift — an aircraft sustains flight past this altitude primarily by its velocity, reaching a speed sufficient to maintain an orbit but not to generate enough lift from the thin air. which choice completes the text with the most logical transition? a regardless, b for instance, c granted, d instead

Explanation:

The text first describes the Kármán line and then the situation of an aircraft. "For instance" is used to introduce an example - the aircraft situation to illustrate a point related to the Kármán - line concept. "Regardless" is too general; "Granted" is more for conceding a point; "Instead" implies a substitution or alternative.

Answer:

B. For instance,