Interspecific competition I believe
D. They make their own food using energy from the sun. Trees use a process called photosynthesis to convert light energy from the sun, carbon dioxide, and water into glucose (the food) and oxygen.
The answer to this is C. Industry. It's the only man made factor.
Male has sex chromosomes: One X + one Y
Female has sex chromosomes: Two X
So, Female must contribute by one X chromosome, but male can contribute either by X or Y, if he sends, X chromosome, then Female (Girl) will form, but if he sends Y chromosome, then Male (Boy) will form
Hope this helps!
