Phloem tissues in plants perform the important function of transporting food, particularly sugars manufactured during photosynthesis, from the leaves where it`s produced to the other parts of the plant. This process is called translocation.

Let`s look at the other options. Option 1 suggested water as the answer, which is incorrect because water is primarily transported by the xylem tissues, not the phloem. Option 2 suggested oxygen. Oxygen, produced as a byproduct in photosynthesis, just diffuses out of the plant. It doesn`t need special tissues to be transported. Option 3 posited minerals, which again is not accurate. Minerals, akin to water, are transported chiefly by the xylem tissues.

Therefore, the correct answer is option 4: phloem tissues are mainly responsible for the transport of food.