Final answer:
Gender does not primarily determine the daily water intake needs. Activity level, body composition, and weather conditions are the main factors influencing water requirements, with the kidneys regulating body water levels.
Step-by-step explanation:
The factors that determine how much water intake is needed on a daily basis are activity level (A), body composition (B), and weather conditions (D). However, gender (C) is not a primary determinant in the daily requirements for water intake. The body maintains water balance and homeostasis through the intake and output of water, influenced by various physiological factors such as hormone regulation, particularly by antidiuretic hormone (ADH).
Water intake is supplied by both consumption through the digestive tract and by metabolic generation at the end of aerobic respiration. Water is lost primarily through urine, but also through sweating, defecation, and insensible water loss such as evaporation from the skin and respiration. The kidneys play a critical role in regulating water levels by conserving water when the body is dehydrated, or by expelling excess water when necessary. Factors like activity level and weather conditions can increase the need for water due to higher rates of perspiration and respiration.