Read the excerpt from A Black Hole Is Not a Hole by Carolyn Cinami DeCristofano, and answer the question.

In this way of thinking, the "background” acted more like a flexible mat, or a stretchy knit blanket. This new, blanket-like idea of space meant space could stretch, crunch up, bend, and warp. Moving objects would follow the curves of the blanket, moving along the surface through flat sections as well as distorted ones. This new idea about space changed the way scientists think about gravity.

Speaking of Gravity: Newtonese and Einsteinese

Most of the time gravity seems to work the way Newton described it. Newton's rules explain a lot, from falling apples to most planets’ orbits. But his laws don't work perfectly. In high-gravity zones, Newton's ideas don't jibe with what scientists observe. For example, Mercury's orbit—up close to the Sun—has a blip in it that Newton's laws can't explain.

Glitches like this one were the reason Einstein worked so hard at coming up with a new explanation. He wanted to account for everything. His ideas about curving space may sound bizarre, but they work! They took care of the gaps in Newton's theory and explained Mercury's orbit. They led scientists to predict shifting starlight and black holes. All of this is powerful evidence that Einstein was on to something.

According to the excerpt, what helped Einstein to draw the conclusion that space was like a stretchy blanket rather than rigid nothingness, as Newton believed?

This new idea about space changed the way scientists think about gravity.
Most of the time gravity seems to work the way Newton described it.
Newton's rules explain a lot, from falling apples to most planets' orbits.
Mercury's orbit—up close to the Sun—has a blip in it that Newton's laws can't explain