The question asks you to conjugate the verb "ser" for first person singular (yo).
The correct form is: :"soy"
The full sentence:
Yo soy alta.
The full paradigm of "ser" is:
yo soy
tu eres
el/ella es
nosotros/nosotras somos
vosotros/vosotras sois
ellos son
Uno debe for the first 2 questions and for the last one it’s
Maria tiene que hablar