^ BTC for sure!
Next halving will occur every after 4 years which makes the price increase the whole crypto market since all altcoins also swing the price when BTC grows up. So it is a safe place to invest BTC because of halving which is expected that it will have a huge impact on the price, we have been proved this for how many years, every halving come BTC price increase massively. Therefore, the best for the long term is no other than aside from BTC. Why we choose altcoin if we don't know them, especially if they also follow the BTC price trend.