The correct letter d is the one marked by the green arrow. This example illustrates the rule always keep going inside the box that you want; in this case, the blue box associated with the letter a of the word had;
d zuzena da gezi berdeak markatutakoa. Adibide honek erakusten du beti egon behar duzula nahi duzun koadroaren barruan; kasu horretan, had hitzari dagokion a letraren koadro urdina.