How to change the font size of select options?

I have select in my form but I can not change the font size of the options.

See image below:

Howtoincreasethefontsizeofthelistofoptions?Ialreadytriedfont-sizeandnothingworked.

HTML

<figureclass="cx-fotos-portugal">

    <form>
    <select>
        <option selected="selected">Escolha a cidade</option>
        <option value="">Cascais</option>
        <option value="">Lisboa</option>
        <option value="">Porto</option>
    </select>
    </form>

    <img src="./fotos-portugal/foto-portugal-capitania-do-porto-cascais.jpg">

</figure>

CSS

figure.cx-fotos-portugal{
    margin: 0 auto;
    width: 100%;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
}

figure.cx-fotos-portugal form{
    position: absolute;
    background-image: url("../imagens/ponto-transparente-seletor-principal.png");
    padding: 20px;
    border-radius: 10px;
}

figure.cx-fotos-portugal img{
    width: 100%;
    height: 100%;
    max-height: 550px;
}

figure.cx-fotos-portugal form select{
    font-size: 35px;
    padding: 5px;
    border: 1px solid #b9bdc1; 
    color: #797979; 
    height: 55px;
}

figure.cx-fotos-portugal form select option{
    font-size: 35px;
    padding: 5px;
    border: 1px solid #b9bdc1; 
    color: #797979; 
    height: 55px;
}