Answer is D.
Spatial locality refers to a data near by a recently accessed one being accesses in near future. So, to make use of it, when a data is accessed, a block of data which incudes the accessed part is taken (called cache line) and placed in cache. So, if this cache line size is 1 byte, that virtually rules out any chance of exploiting spatial locality in cache.
A is not correct. There is no "remembering" mechanism in cache though this might be used for cache line replacement like in LRU.
B is for temporal locality.
C is used for write-back cache.