Only the first comment is accurate. The basis of a hedge refers to the difference between the spot price of an asset and the futures price of a contract for that asset. When the spot price increases relative to the futures price during the hedging period, the basis is said to be strengthening. This is because the spot price is moving in a direction that is favorable to the holder of the futures contract. The holder of the futures contract would be able to sell the asset at the higher spot price and buy it back at the lower futures price, thus making a profit. This is the essence of hedging - to protect against adverse price movements in the market. Therefore, the first comment correctly encapsulates the concept of a strengthening basis in the context of a hedge.

Choice B is incorrect. The second comment incorrectly defines basis risk. Basis risk is not the risk that the volatility of a futures contract will not move in line with that of the underlying exposure. Instead, basis risk refers to the risk that the price difference between a futures contract and its underlying asset (the basis) will change unpredictably over time.