In winter, snowmelt pools in fractures and other cavities, then freezes and expands, breaking off chunks of sandstone.

what does cavities mean as it is used in paragraph 4? (note - this is the paragraph that the excerpt was taken out of.)
a.
new small fractures
b.
small colorful patterns
c.
small hidden holes
d.
new colorful lumps

if you could answer i'd appreciate it a lot. x

I remember when I got my first $1000 when I was 16 and I decided to go to a fancy restaurant with my girlfriend. I checked a list of restaurants around and settled on an Italian restaurant. I got her quite an expensive flower as I went to pick her up, of course, she was excited and looked really beautiful in her blue gown. I contemplated canceling our date and ravishing her right there and then but I took a deep breath and smiled back to her, gave her a hug, and off we went to the Italian restaurant.

We got to the restaurant fifteen minutes later, got to our seats, and ordered their special dish which was really nice. All eyes were on us right from when we stepped into the restaurant because we looked like the power couple, I mean it was great to be the cynosure of all eyes.

Some minutes after our meal and having a dessert, we were having a vintage drink and I was slightly tipsy. We were laughing a bit loudly and then without warning, I threw up all over her blue dress and it was really humiliating. I had never felt so embarrassed in my life.