Earth's magnetic field used to be twice as strong 1.5 billion years ago as it is today and Earth's temperature other than what the geologists see from the 'normal' pattern. It has been noticed that some volcanic rocks were magnetized in opposite direction to the direction of the local Earth's field. It is clear that the Earth has experienced the normal polarity 1.5 years ago but at that time, the Earth's polarity was poorly understood.
I believe the correct answer among the choices given above is option B. It is the tissue called phloem that the food travel from the leaves to the bulb. Phloem is a vascular tissue in plants that process sugars and other products.Hope this answers the question.
