The clean way to resolve this fact pattern is to treat the deed as containing three separable promises, the gift for the library, the reversionary condition, and the accumulation direction, and assess each one under its own rule rather than as a single indivisible transaction.
Separating the deed into its three components shows that the transfer for the library and the reversionary condition both stand, while only the accumulation clause is void beyond the statutory period, which is exactly the fourth option.
Two pairs of options are worth comparing directly here: the pair disagreeing about whether the perpetuity problem kills the whole gift, and the pair disagreeing about whether public-purpose transfers escape the accumulation limit altogether.
By keeping the perpetuity exception and the accumulation cap analytically separate, only the option preserving the gift while trimming the excess accumulation period survives scrutiny.
Therefore, the correct answer is the transfer is valid as it falls within the exception for public benefit, but the accumulation clause is void to the extent it exceeds statutory limits.