 
 <prompt> Wetin be di wahala with di patent? Based on di last question, write a context wey contain di answer. E fit be 1 - 20 sentences. Context: <response>: The matter of who suppose get priority for the variable resistance feature of di telephone na di question wey di examiner raise before e approve Bell patent application. E tell Bell say im claim for di variable resistance feature dey also inside Gray's caveat. Bell show am one variable resistance device wey dey inside Bell previous application wey Bell describe as cup of mercury, no be water. Bell don file di mercury application for di patent office one year earlier on February 25, 1875, long before Elisha Gray describe di water device. Plus, Gray abandon im caveat, and because e no contest Bell priority, di examiner approve Bell patent on March 3, 1876. Gray don reinvent di variable resistance telephone, but Bell na di first wey write down di idea and di first wey test am for inside telephone. 