Estas is the feminine plural form of the demonstrative adjective este that is used to point out something near to the speaker in space or time. This type of adjectives demonstrate a quality about the noun they modify. Here that quality is the location in respect to the speaker or the listener.Since botas is a feminine plural noun, we use estas. Finally:
Habia because Habia means there were. On the other hand we have contaba which men tell, saludaba which mean said hi, and nacia which means born. so your best bet is Habia
