Why does the MC Curve cut the AVC curve at the AVC Curve’s lowest point?

When marginal costs start to rise, starting at point C, due to diminishing returns, the average variable cost is still decreasing, at point X. The average variable cost will continue to decrease as long as the marginal cost is lower than it. Likewise, the average variable cost will increase, at point Y, if the marginal cost is higher than it. When the average variable cost is equal to the marginal cost, at point Z, the average is constant which is why the curves intersect at the lowest point on the AVC curve. If put into practice, this would happen: A start-up business will not run as efficiently as it can at the beginning. It will have to start with a few employees that it can afford in its budget. After time, more extra employees are added and learn to specialise, out will increase and the marginal cost per unit will decrease, at point A. This will decrease the AVC curve at point X. However, with each unit of labour being added, a point of maximum efficiency is obtained, at point C, and instead of decreasing marginal costs, they increase, at point B, thus reinforcing the law of diminishing returns. However, this law is only applied to the AVC curve when the AVC curve and the MC curve are equal. Before this, MC will pull the AVC down and after this, the marginal cost pull the AVC up, at point Y.