Imagine an advanced civilization living on a planet orbiting at a distance of 10 AU (1.5 billion kilometers) from a close binary star system that consists of a 15 MSunred giant star and a 10 MSunblack hole. The black hole is surrounded by an accretion disk. Sometime within the next million years or so, the civilization's planet is likely to be doomed because .

a. the planet's orbit gradually will decay, as it is sucked in by the black hole.

b. the red giant star, which provides most of energy the civilization needs to exist, will soon be destroyed in the accretion disk.

c. tidal forces from the black hole will rip the planet apart.

d. the red giant will probably supernova within the next million years.

e. jets of material shot out of the accretion disk will shoot down their planet.

Option D: the red giant will probably supernova within the next million years.

Explanation: a black hole is termed as object that has great gravity that nothing e.g like light can escape it.

A red giant star are usually a star that is dying at the last stages of stellar evolution. A supernova does occurs in Galaxy like milky waves at least only one time in 50years and can be liken to star destruction or exploding nearby universe which is sometimes closer to earth. There are 2 different ways a star can supernova. They include a Type I supernova which involves a star gathering (accumulating) a neighbour's closeby matter till runaway nuclear reaction light up (ignites). The other Type II supernova are star which their nuclear fuel has run out and then

breaks down(collapse)by or due to its own gravity.

competition i thin

could you show the options for the answers? : )