It is possible to produce seedless tomato fruits by

The correct answer is C because seedless fruits can be produced through a process called parthenocarpy. This process involves the development of fruit without fertilization. By spraying specific plant hormones, such as auxins or gibberellins, onto the flowers, the ovary is stimulated to develop into a fruit even if pollination has not occurred. Since no fertilization takes place, the resulting tomato is seedless. Options A, B, and D involve soil nutrients or radioactive elements, which may help in plant growth or research but do not directly trigger the biological mechanism for seedless fruit formation.