Answer:
The correct answer is option B (negative gravitropism) and option C (positive phototropism).
Step-by-step explanation:
Plant seedlings shows downward growth of roots and upward growth of stems due to response of plants to external environmental stimulus via a phenomemon known as tropism.
Plant tropisms are the result of differential growth as cells in area of stem or root grows more quickly than cells in opposite area.this growth determines the directional growth of the entire plants. The directional growth of an organism in response to light is known as Phototropism while directional growth of an organism in response to gravity is known as gravitropism.
Shoot growth in plants shows negative geotropism because they grow away from that force or in opposite direction of the gravity. Also, plants shows positive phototropism as they respond in direction of light.
Thus, option B (negative gravitropism) and option C (positive phototropism) are the right answer.