They are multicellular organisms. In plants there are two types of reproduction :- sexual and asexual. Sexual reproduction happens when androecium and gynoecium both fuses and in asexual reproduction when only androecium or gynoecium is present in a plant. Androecium us a male part off flower and gynoecium is the female part of flower. Plants can't move that we all know and they are autotrophs coz they can make their own food in presence of sunlight, water, air and chlorophyll.....
I think the correct answer from the choices listed above is option B. You can find methanogens in the human intestines. These organisms can work with or without oxygen. Too much of oxygen for them is toxic. They are obligate anaerobes.