As Texas was defending its claim to be a new and independent republic in 1836, a final crucial victory was won at

ASan Jacinto.
BLas Cruces.
CSan Antonio.
DGoliad.

Verified Answer :

As Texas was defending its claim to be a new and independent republic in 1836, a final crucial victory was won at "B. Las Cruces" although it wasn't enough to evade disunion.