Marca, señal, palabra o escrito breve que se pone en un texto para comentar, aclarar o completar algo que se menciona en él.
"nota marginal"
2.
Escrito breve en un papel u otro soporte con el que se avisa de algo o se recuerda algo.
"bloc de notas"
Explanation:
Mark, signal, word or brief writing that is put in a text to comment, clarify or complete something that is mentioned in it. "headnote" 2. Briefly written on a paper or other medium with which something is warned or something is remembered. "memo pad"
it came down to either "lo" or "la", lo is masculine and la is feminine. So the answer was lo because if there is no signs that the sentence is feminine then you just use the masculine word/s.
