The words ended and theory
Answer:
B, On September 23, 1999, NASA officials were aghast when the $125 million Mars Climate Orbiter vanished as it prepared to enter the red planet’s orbit.
Explanation:
The use of word imagery and mystery make this a good intro sentence. MAKE SURE IT MAKES SENSE THOUGH! I can't see which sentence is supposed to come after this, so make sure it makes sense with the paragraph
