Recurrent neural networks (RNNs) and their variants (such as LSTMs and GRUs) are designed to handle sequential data , capturing dependencies across time or position in a sequence. In language translation, words and phrases must be interpreted in context, where the meaning of a word depends on preceding (and, in advanced architectures, following) tokens. RNNs maintain internal state across steps, allowing the model to encode information from earlier parts of the sentence when predicting later outputs.

Option B (association rules) refers more to classical data ‐ mining methods, not the core reason RNNs work for translation. Option C (grid data) is more relevant to convolutional neural networks used for images. Option D (unidirectional) is not inherently an advantage; in fact, bidirectional models are often preferred. Therefore, the key property enabling RNN use in translation is the sequential processing capability.